Ok, first I never said Cienie devs weren't at fault, you just made that up.
As it seems the rest of your message, But I will bite.
Cienie devs never said there is going to be sex in their visual novel.
In fact, you can scroll through the page and you will find it.
Also It's a furry fandom everyone turns sfw things into nsfw art they enjoy, and the false "promo" art you spoke off is just artistic nudity.
Beside it wasn't even promo art... It was Just simple thank you art and Christmas wishes.
And before you bring up that people behind the cienie draw art of their character in nsfw poses, yes they did.
THEY'RE ALLOWED TO.
It's their right to do so.
So please stop trying to blame them for everything when you clearly don't grasp the situation.